Answer:
Customer complaints is the correct answer.
Step-by-step explanation:
Complaints should not be ignored as they allow us to know what is wrong and what to improve in the business. The customers are in a unique position, to tell the truth about the product and service. Most of the studies regarding customer complaints confirm that those companies are more successful who listen to the customer complaint and act on them. The company's sales force must be trained to listen to the complaints carefully and to view it as an opportunity to build stronger relationships with customers.